The present invention relates to a heat exchanger that prevents deformation due to thermal expansion of a core in operation in a radiator for automobile or the like.
As shown in FIG. 7, a heat exchanger for cooling engine cooling water includes flat tubes 1 and corrugated fins 2 alternately arranged in parallel with one another. Both ends of each of the flat tubes 1 are inserted into a pair of tube plates 4 to form a core 3. A not shown tank main body is mounted on the each tube plate 4, and side members 5 are disposed on both sides of the core 3.
The side member 5 includes side walls at its intermediate part in the lengthwise direction, having U-like cross section, but does not have side walls at both ends.
The cooling water at high temperature resulting from cooling the engine is guided from the tank main body at one side to the other tank main body through circulation in the each flat tube 1. An air blowing operation is carried out toward the outer surface side of the flat tube 1 and the corrugated fin 2 side for heat exchange between air and the high-temperature cooling water.
Circulation of the high-temperature cooling water in the flat tube 1 will extend the flat tube 1 and the corrugated fin 2 in the lengthwise direction of the flat tube 1, and expand them also in the direction orthogonal to the lengthwise direction. Meanwhile, the temperature of the side members 5 at both sides of the core 3 hardly changes to maintain the state.